Bar-heating furnace



' Nov. 19, 1929. F W, BROOKE 1,736,248

BAR HEATING FURNACE Filed DGC- 51, 1927 2 Sheets-Sheet l WlTNESSES INVENToR MQ M Bhal,

I I n Nov. 19, 1929.

BAR HEATING FURNACE F. w. BROOKE 1,736,248

Filed Deo. 3l, 1927 2 Sheets-Sheet 2 l INVENTOR Patented Nov. .419, 1929 PATENT oFF'lcE FRANK BROOKE, F PITTSBURGH, PENNSYLVANIA BAR-HEATING FURNACE lApplication led December 31, 1927. Serial No.\243,8 51.

In the heating of comparatively' thin bars of iron and steel, such as sheet bars, in furnaces of the continuous type, it has been the practice to feed the bars through the heating-chamber on edge and in backwardly inclined position in order to prevent their falling forwardly, a support being provided at the rear of the row in order to prevent their falling backwardly. In such arrangement of the bars portions of their flat surfaces are directly exposed tothe iame in the heating chamber, and while these directly exposed flat portions are comparatively small, they are nevertheless to that extent the more exposed to scaling, and this often results in an ununiform surface' on the final sheet. It is the object of the -invention to provide means whereby the bars in their progress through the heating-chamber of the furnace will be maintained on their edges'inupright position, and consequently 'the'unevenness of heating referred to ,will be avoided. In the accompanying drawings Figure 1 is a central sectional elevation'of a continuous heating furnace'embodying -the invention in its preferred form, and Figure 2 is asectional plan View, it bein understood that in normal operation the bo will be filled with bars being heated. Figure 3 is a detail view of the pusher at the front of the furnace. v

The furnace may be any well known or suitable type of continuous heating furnace, such for instance as that shown in-Let'ters f Patent No. 632,020, in which the'A pieces being heatedare pushed in contiguous succession upo'nja track extending through the heatingchamber. I have shown in the drawings, however, a furnace intended for the pairheating of sheet-ba-rs, which rest on edge on the trackin their passage throu h the heating-chamber. This furnace, as s own in the drawings, 1s provided with `a combustion chamber'l for heating by means of coal, using a standard form of Stoker, the flame and products of combustion flowing over the bridgewall 2 into the heating-chamber 3, and thence 4through the heating-chamber and out through' the iues, 4, 4, at the opposite or rear end of the heating-chamber, and into the stack-Hue y of the heating-chamber 5. But'the character of fuel employed and' the manner of its introduction into the heating-chamber are not material to the invention. g The bars or billets being heatedare caused to pass through the heating-chamber 3 on 55 ways which are elevated above the floor 6 of ythe chamber, with the space beneath the ways in open communication with the body of the chamber. These ways preferably consist of hollow water-cooled skid-pipes 7 of well 60 known formv which are laid in the top surfaces of pedestals 9 arranged at intervals in rows longitudinally of the chamber. Thus a pair of the longitudinal skid-pipes 7 con- 4 stitutesa trackthrough the chamber for the bars or billets. o Y

In the heating-chamber the space 13 underneath the bars on thetrack is inopen communication with the bodyof the heatingchamber through the openings 14 between 70 the pedestals 9. --In order to draw active curlrents of the heated products of combustion around and underneath the bars, flue-ports 15 are formed in the Hoor 6 of the chamber beneath the track and are connected to,` a flue 16 underneath the floor, the latter opening into the stack-iue.

The charging-opening 20 of the furnace is -formed in the front end-wall 21 and is provided` with a vertically sliding door 22. y The I tilted backwardly. Furnacesof this class are usually operated in what -is known as the semibatch method, that is'to say, a-number of sheet bars, on their edges, covering a length 9a of two or three feet, are pushed into the furnace'at one time; At the discharge end the bars are withdrawn until a number of bars equal to the charge havebeen sent to the rolls, and then a fresh batch is pushed intothe 1.99-

80. reciprocable pusher-head 23 maybe operated iml furnaces The strength of the springsvis heating chamber, will not be sufficient to -force the face-plate 24 backwardly, but when in the l operation of charging the furnace the bars being charged come into contact with the bars already in the furnace, the sprin s 25- will yield so that the face-plate. 24 an the bars will assume an upright position and the bars will be charged into the furnace standing vertically upon their edges.

.j For retaining the row of bars in the heatlng chamber and preventing them from falling backwardly, a suitable automatic latch or support 27 is provided. One form of such a latch is shown herein. 'It comprises the head 28 mounted on the outerl end of the arm 29 which projects inwardly. below thefchamber, and the inner end of which is fastened to` a shaft 30, which carries at one 'side of the furnace the.' weighted arm 31. The latch Jworks through a slot or recess in the .sole-I plate 32 at the furnacerdoor. The inner-face of the head 28 is shaped to support the barsV in upright position, and its body portion slopes outwardly and downwardly in an inclined outer face .33.- Alll/.Then the`l bars are pushed into the furnace the-head 28 is forced downwardly below the face of the sole-plate '32, and it is held down until the'outermost bar'has passed theapex of the inclined face 33. `Then as the pusher-head is withdrawn ment o the weighted arm 31 causes the upward move-y the head 28 into supporting contact with the rearjface of the outermost-bar in the furnace, thus holding thebars from falling backwardly.y The furnace door 22 can be raised and lowered in any suitable way, and

"is preferably slotted to fit the head 28.

In order to` revent the row of bars from falling forwar l a detent 35 is provided at the exit endof .theY heating chamber, which is shown in the drawings in its preferred form.

This detent comprises a pair of lever arms 36 fixedy to vthe transverse' shaft 37 and projectaing forwardly, .so that'their outer ends lie 1n the path of thel upper edges ofthe bars l'a-t'the exit end of the furnace.

a rock-shaft supported in bearings 3,8 in thc- *opposite side walls fof the furnaceand is pro- This shaft is vided at' one side outside the furnace wall with the weighted arm- 39, which normally holds the lever arms 36 in frictional yielding contact with the upper edges of the 'bars at the exit end of the rnae.

In filling the heating chamber at the start,

L .a suitable dummy, which-may be an bar of theopposite end,I the lever arms suitable size and weight to prevent t e sheet barsfrom falling forwardly, will be fed'in' in advancejofl the sheet bars. Thereafter the feeding will continue iuntil the `furnace is filled and the dummy has been discharged at.

36 serving to hold thel sheet bars at the exit end of thel heating chamberin the vertical position shown in Figure l, and the charging device as already described is utilized intermittently to charge each batch of sheet bars into the heat- A passage through it for a cooling fluid, inletl andoutlet pipes 42 and 43 being lprovided for that purpose. l

I claim as my invention:

1. In a furnace for heatin sheet-bars having a heating-chamber an a supportingtrack forthe bars arranged in said chamber,

'.means arranged at one end of said track for impelling the bars broadside on edge and in contiguous succession upon. and Aover said track, means arranged adjacent to said entrance end of said track for engagingy the rearmost bar on the track and preventin barsA from falling backwardly, and yie ding means arranged Vto bear upon the upper edges the of thec bars adjacent to the opposite end of said track for .preventing the bars from falling forwardly. v .l v

2.` A furnace for heating-sheet-bars having a heatingzgf-chamber,` and apsupportin -track for the bars arranged in said cham r, in combination with bar-pushing mechanism arranged at one end of said track for impelling the bars broadside on edge and in contiguous succession upon and over said track, said bary pushing mechanism having a face-plate pivotally connected thereto and meansyieldingly holding said face-plate in position backwardly inclined to the horizontal.

3. In a furnace for heatinflI sheet-bars having a heating-chamber and .a supportingtrack for the'bars arranged in said c means arranged at ,one end of said track for limpelling the bars broadside on edge and in amber,

contiguous .succession i upon and over saidA track, mean arranged adjacent to said en-l trance`end of said track for engaging the rearvmost bar on the track and preventing the bars from falling backwardly a transverse rockshaft above the bars in the heating-chamber adjacent to the opposite end of said track,

means connected to said shaft adapted to bear- .upon the'upper edges of the bars for preventmg the bars from falling forwardly, and yielding means for holding said'bar-retaining means in operative position.

i myhand.

` v FRANK `W. BROOKE.

In testimony whereof I have hereunto 

